What should you do before prescribing antiemetics?
Evaluate and correct the cause of n/v
Improvement of n/v should been seen how long after pharmacologic intervention
What reverses dig toxicity?
What is an example of an antidopaminergic drug?
**QUESTION from last year!
Compazine or phenergan
What is the MOA for phenothiazine antidopaminergics? What is an example?
Block D2 dopamine receptors in the CTZ(chemoreceptor trigger zone) and in other areas of the brain. Have anticholinergic and antihistamine effects. results in sedation, muscle relaxation and hypotension.
Example: Compazine, Phenergan
What is the MOA for benzamide antidopaminergics ? What is an example??
prevents stimulation of CTZ by antagonizing central and peripheral dopamine receptors. accelerates gastric emptying.
**used in the prevention and management of chem n/v.
Example -- Reglan
What is the MOA of anticholinergic agents?
What are some examples of drugs in this class?
these have an antiemetic, anticholinergic and antihistaminic property. They reduce the sensitivity of the labryrinthine apparatus. Exact MOA unknown.
examples - Meclizine, Dramamine, transdermal-scopalmaine (inhibits vomiting reflex)
Antihistamines/Anticholingerics are effective for which cause of n/v?
take 30 to 60 mins before the event and at regular intervals. if using patch.. replace every 3 days.
NK1 Receptor Antagonist
very effective in treating n/v especially with chemo but they are very expensive!!
example -- emend
What is the MOA of Serotonin 5 HT3 Receptor Antagonists?? What is an example of this drug class?
What labs with this test?
Work peripherally in the intestinal wall by blocking 5HT release and block 5Ht receptors in the CTZ
Baseline and follow up LFT
Benzodiazepines work by???
What is most frequently used?
treating and preventing emesis. They have anxiolytic and amnesiac effects. (useful in anticipated n/v)
Lorazepam (Ativan) is the most frequently used benzo for n/v. MOA not clearly understood.
What drugs should you use for chemo induced n/v?
QUESTION ON TEST last year!
5HT3 (Zofran), Metoclopramide (antidopaminergic) and corticosteroids?
If vomiting is not controlled what is your biggest concern?
- 'lyte disturbanes
- m. acidosis
What are 3 things to remember when prescribing antidopaminergics/phenothiazines?
highlighted in notes
- 1. These drugs should not be taken with other drugs that cause CNS depression. Risk for oversedation
- 2. Can exacerbate the s/s of Parkinson disease. -Test!!!!
- 3. Can provoke extrapyramidal symptoms by blocking dopaminergic receptors involved with motor function. (such as lip smacking -- can treat with Benadryl 25mg 3xdaily!)
You should prescribe anticholinergics with caution to individuals with ___?
Use with caution with what other disorder commonly seen in elderly?
asthma... will dry them out!!
narrow angle glaucoma, and prostate disease.
What is a side effects seen with NK1 Receptor Antagonists (Emend)?
- also HA, diarrhea, constipation, extreme fatigue
- use care with drugs that use p450 system
What is normally most helpful when treating geriatric patients with n/v?
with treating the elderly you're concerned of oversedation and worried about difficulty in treating with renal impairment... therefore the best thing may be bowel rest with only clear liquids for 8-10 hours with these patients instead of prescribing medications!
- do not use benzos with this population.
- keep elderly hydrated!!
- Remember... elderly drink but often wont tell you this because its considered a norm for them.. ETOH can cause additive effects.
What is the recommended treatment for the peds population with n/v?
24 hours GI rest with clear liquids if uncomplications vomiting.
risk for hallucinations, decreased alertness or excitation, Reye's syndrome (contains aspirin often---pepto), and extrapyramidal symptoms.
If you must prescribe an antiemetic for a child, which 2 drugs could you use?
- Promethazine/dimenhydrinate -- but not if <2yrs
- on old test review.. states that Phenergan has a black box warning and should not be given to children!?
- ondansetron (Zofran) ---but not if <4yrs.
What drug can a preggo lady take for nausea/vomiting?
NONE... should be approved by obstetrician.
antihistamines are thought to be safe but shouldn't be used in the 1st trimester.
nursing mothers should not use these drugs either!
What coordinates the respiratory and vasomotor centers and vagus nerve innervation of the GI tract?
Vasocenter in the medulla.